Different criteria must be met for the manufacture of jewelry, frames for glasses, metal parts to be worn on the body or clothing, in order to be able to utilize the product in practice. The manufactured products must, on the one hand, be sufficiently strong, on the other hand, the optical demands must be met. The problems of strength exist in particular in the case of frames for glasses, for example in the frames around the lenses or the temples. It is also absolutely essential for other jewelry, for example pins, rings, earrings, chains, bands or others that the alloy has given strength factors in order to avoid mechanical damage thereto. Furthermore, physical characteristics must be met for certain uses, for example with respect to heat conductivity, coefficient of linear expansion, electrical resistance and electrical conductivity. A further criteria for selecting such an alloy is its manufacturing capability. The alloy is supposed to be both easily pourable in order to facilitate manufacture of the necessary blanks, for example through extrusion or casting in molds, and also be moldable in order to be able to create out of the alloy, for example, rods, wires, bands or similar items. Alloys, which partly or completely meet the above requirements, are for example described in Gebrauchsmuster 90 17 408.9 or the DE-OS 38 34 186. Also DE-PS 26 26 251 describes such an alloy.
The mentioned alloys are distinguished altogether by containing a relatively high nickel content. This nickel content is increasingly undesired in jewelry, frames for glasses and similar articles which are worn directly on the skin, since many people are allergic to nickel. Among others, caused by the increasing environmental burden, the percentage of the population suffering from such allergies is increasing so that nickel-containing alloys are more and more not accepted by customers. Help exists in some cases due to coatings or envelopes, however, this is not possible in most cases of use.
The purpose of the invention is to provide an alloy of the above-mentioned type which can be manufactured inexpensively and easily, has high mechanical strengths and no nickel content.